680 fF, W. SARDESON 
shows one-half the area to be probably Cretaceous, beneath the 
drift. Further geological investigation must of course tend to 
lessen this enormous difference between the known and the 
possible Cretaceous. During the last two summers I have had 
opportunity to investigate the supposed Cretaceous in south- 
eastern Minnesota with the surprising result that the reported 
areas and deposits, in some instances prove to be doubtful. 
In this region, there have been mapped, as mentioned, prob- 
able Cretaceous areas, covering a small spot in Goodhue county, 
patches in Fillmore county, and a continuous area in Steele, 
Dodge, Mower, Freeborn, Faribault, Blue Earth, Brown and 
other counties. The reported known areas are that of Goodhue 
county, some clays in Mower county, near Austin, and gravels 
near Hamilton, small pockets of clay in Blue Earth and Scott 
counties and certain strata in Brown and Nicollet counties. 
The last named is very probably Cretaceous. Near New 
Ulm, Brown county, have been found fossil leaves which are 
described by Leo Lesqueseaux' and referred by him to the 
Dakota group. I have visited the same locality and collected 
some of these fossils, which are abundant only in a thin discon- 
tinuous stratum of fine sandstone. The whole bed, consisting 
of coarse sand with some irregularly distributed clay is 30 feet 
or more thick and rests upon a rotted granitoid rock, which 
rises 10 feet above the level of the Cottonwood River. The 
tossil leaves were found a few feet only above the sandstone’s 
base, in a layer which has a concretionary-like surface, and 
except for its width of several feet might be called a pebble, 
which other smaller fossil-bearing concretionary masses in the 
same zone certainly appear to have been. The leaves are found 
therefore in a broken stratum, which, however, was, with little 
doubt, contemporaneously deposited and broken, so that the 
contained flora is indicative of the formation’s age. The materi- 
als of the sandstone are imperfectly asssorted and again almost 
arcose in character. : 
Other sand and clay exposures of the same age have been des- 
™Minn. Geol. Surv., Vol. III. 
